14. Longest Common Prefix

找出n个字符串的最长前缀

public class Solution {    public String longestCommonPrefix(String[] strs) {        if(strs.length == 0) return new String("");        if(strs.length == 1) return strs[0];        StringBuilder stringBuilder = new StringBuilder();        int min_len = 2147483647;        for(int i = 0; i < strs.length; ++i) {            min_len = Math.min(min_len, strs[i].length());        }        for(int pos = 0; pos < min_len; ++pos) {            boolean ok = true;            boolean flag = false;            char c = ' ';            for(int k = 0; k < strs.length; ++k) {                if(!flag) {                    c = strs[k].charAt(pos);                    flag = true;                } else {                    if(c != strs[k].charAt(pos)) {                        ok = false;                        break;                    }                }            }            if(!ok) return stringBuilder.toString();            stringBuilder.append(strs[0].charAt(pos));        }        return stringBuilder.toString();    }}